A Food and Drug Administration advisory panel voted on September 23 that the benefits of Grail's Galleri blood test outweigh its risks, backing what would be the first multi-cancer early-detection test to reach the U.S. market with full agency approval. The vote came after two days of testimony reviewed by STAT News and NPR.
The FDA's Molecular and Clinical Genetics Devices Panel split three ways. Members voted 10-0 that Galleri is safe, 6-4 that it is effective, and 7-2, with one abstention, that its benefits outweigh its risks for people age 50 and older who have no cancer symptoms. Galleri screens for patterns of DNA methylation in cell-free DNA circulating in the blood; a positive signal is meant to flag a likely cancer and its probable location in the body, prompting follow-up scans or biopsies rather than serving as a diagnosis on its own.
A test that missed its own goal
The closest vote reflected a real gap in the evidence. Grail's own PATHFINDER 2 study, which enrolled more than 35,000 people age 50 and older in North America, reported 69.8% sensitivity for 12 cancers that account for roughly two-thirds of U.S. cancer deaths, with 99.6% specificity. But the trial did not meet its primary goal of reducing the combined rate of stage III and IV cancer diagnoses, and neither it nor the roughly 140,000-person NHS-Galleri trial in England, where sensitivity ran lower at 31.6%, has yet shown that screening with the test reduces cancer deaths.
"Routine approval and broad population rollout would risk harm and waste resources."
Phil Castle, Director, Division of Cancer Prevention, National Cancer Institute
Other panelists framed the missing mortality data as an acceptable trade-off given how many cancers currently have no screening test at all. "It's a new era for early cancer detection, and if the FDA approves it, it validates the overall concept," Cristian Tomasetti, who directs early detection research at City of Hope, told the committee, according to meeting materials. Grail has also pointed to a later look at NHS-Galleri data showing standalone stage IV diagnoses fell over three years of follow-up, a signal the company says points toward earlier detection even without a full mortality readout.
The FDA is not bound by its advisory committees' recommendations but usually follows them; a final decision on Galleri's premarket approval application is expected within months. The test, which holds an FDA Breakthrough Device designation dating to 2018 and is currently sold as a lab-developed test without full agency clearance, would need that approval to be marketed nationally as an FDA-cleared multi-cancer screening tool alongside routine mammograms and colonoscopies rather than in place of them.
